This is a proposal to continue a longitudinal study of health based on a community cross section of youths now in their early twenties, who are from an urban, mostly black, ghetto area. Its purpose is to look at patterns of drug use (alcohol and other drugs used non-medically) and changes in these patterns over time -- in relation to physical, emotional and social antecedents, measured six years earlier. It traces these attributes over the peak years for induction into and dependence on drug use. It examines these patterns in relation to cohort or historical time as well as to age or developmental time -- with a high risk population, both men and women--considered at high risk of drug use because of their position both in society (minority group) and in the life cycle (youth). By applying procedures which are capable of probing motivations and reactions in a community cross section sample (personal interview), this study also will investigate attitudes and behavior that have relevance to drug use prevention (e.g. motives for avoiding drugs), for intervention (e.g. motives for stopping use) and for rehabilitation (e.g. attitudes toward and experiences in obtaining treatment for drugs). This research will build upon an unusually comprehensive set of health data collected through personal interviews and medical examinations with a community sample of 752 adolescents aged 12-17 in 1968-70. It also builds upon the first stage of the follow-up which tested re-interview procedures on the oldest seqment(N equals 141) of the original sample,namely: a) tracking respondents' addresses; b) recruiting and training interviewers in obtaining information about personal matters such as use of drugs; c) protecting the privacy of respondents and the confidentiality of their replies; and d) the schedule of questions for the new personal interview.